Compress a PDF for an admin portal
The tax portal rejects your return attachment, the visa application refuses your bank statement, a benefits platform bounces your supporting document: administrative portals almost always cap each uploaded file — typically between 1 and 10 MB on modern services, sometimes far less on legacy forms. The right size is not “as small as possible” but “just under the required cap”. The “target size” field is pre-filled at 976 KB — a safe value under the decimal “1 MB” bound of the strictest portals — and accepts the exact limit your process states: the tool then recompresses in steps, the DPI and JPEG quality of rasterized pages decreasing rung by rung, until the file passes under the threshold. If the quality floor is reached first, the best result achieved is shown honestly — splitting the document or sending only the required page then becomes the winning strategy. Everything runs in your browser: neither your income statement nor your certificate leaves your device — no small point when the file carries a tax ID, company number or bank details.
FAQ
What limit do government and admin portals enforce?
Each portal sets its own per-file cap — commonly a few MB on modern services, ~1 MB or less on legacy forms. The exact limit is stated on your portal’s upload screen: type it into the “target size” field rather than guessing.
Why 976 KB and not 1,024 KB?
Your system displays binary MiB (1 MiB = 1,048,576 bytes) while many portals measure decimal MB (1 MB = 1,000,000 bytes): a “1.0 MiB” file exceeds a “1 MB” limit by about 5%. The pre-filled 976 KB passes under both conventions.
My 8-page scan will not fit under the cap — what now?
Two complementary levers: send only the page(s) requested — extract them first with “Extract pages” or “Split PDF” — then compress that fragment; a one-page PDF goes far lower than a whole file. If the portal accepts several files, split and compress each part separately.
Will my document text stay readable and selectable?
In most cases yes: the smart strategy keeps text pages as vectors and only rasterizes image-dominated pages. Fidelity on rasterized pages is measured (SSIM) and shown before download — check it before uploading an official document.
Is it safe for a file containing my tax ID or IBAN?
Analysis, rasterization and PDF rewriting all run locally in your browser: no byte of the document transits through a server. You can verify this in the Network tab of your developer tools — unlike classic online compressors which send the file to their infrastructure.
The portal still rejects my file though it is under the cap?
Check the unit shown by the portal (KB vs KiB, MB vs MiB, decimal or binary) and the required format — some forms only accept PDF, others reject password-protected files or portfolios. “Unlock PDF” can help in the latter case.
What if the best effort stays above the threshold?
The loop stops at the quality floor and the size actually reached is displayed — never a false promise. Reducing the page count is then the most effective lever: a PDF’s floor weight mostly depends on how many pages must be rasterized.
How to proceed
- Check the exact limit stated by your portal (MB or KB)
- Drop your PDF — the “target size” field is pre-filled at 976 KB; adjust it to your portal’s cap
- Run the compression: the tool steps down until the threshold or the quality floor
- Check the size reached and the fidelity (SSIM) before uploading
- If the cap stays out of reach, extract the requested pages then compress the fragment